1. Field of the Invention
The invention relates to surgical devices, and more specifically to surgical retractors for displacing organs and tissues and maintaining them in a specific position in a surgical environment.
2. Description of the Related Art
During surgery, a physician will typically work on a small area or portion of a patient and will need to push the organs and tissues that are not being treated away from the area in question. Alternatively, a physician may need to treat the underside of an organ (or another inconvenient or difficult to reach surface or section) and will need to prop it up for an extended period of time. Surgeons employ several different means of maneuvering organs and other body parts away from a surgical site and keeping them out of their way.
One common method uses common gauze or sponges. The surgeon essentially props up a neighboring organ with a wad of gauze or a sponge to keep the organ out of her field. This method has several drawbacks. First, surgical sponges and gauze are extremely flexible and pliant and do not offer much resistance. As a result, the organ or tissue has a tendency to flop over or push the sponge or gauze out of the way. Additionally, sponges and gauze are difficult to position or mold properly in the first place. Also, as their name suggests, sponges are extremely absorbent. Since the field is filled with bodily fluids, the sponges are constantly absorbing those fluids, which has a deleterious effect on the sponges' rigidity and ability to keep back the organ or tissue.
U.S. Pat. Nos. 6,254,534 to Butler et al., 6,142,936 to Beane et al., and 5,159,921 to Hoover describe tubular-shaped retractors which laterally pull apart a wound opening for access into the field. These patents are silent as to the shifting of organs or blood vessels within the field, i.e., they do not teach or suggest an intra-corporeal retractor at all. U.S. Pat. No. 6,090,041 to Clark et al. describes a vacuum-actuated retractor for retracting body tissue during surgical procedures. One end of the retractor is adapted to seal with a body tissue such that a suction force is applied to the body tissue when the device is activated. A detriment to Clark's device is that the device cannot be molded to fit a specific irregular space or retain a variety of different structures as it is non-malleable. There is also a potential risk of injuring the tissue by application of the vacuum suction.
U.S. Pat. No. 5,460,621 to Gertzman et al. describes a composite tissue displacement sponge having multiple layers of rigid, compressed, absorbent poly vinyl acetate material. The sponge may be compressed into a rigid and dry form which allows the sponge to conform to a precise space of the cavity or site required for organ displacement or protection. The sponge may be hydrated to expand it. This device works suitably as a sponge, however it fails as a retractor that does not react at all with the organs or tissues it retains, because it is constantly absorbing fluid.
U.S. Pat. No. 4,889,107 to Kaufman describes a surgical retractor having a non-absorbent barrier member surrounding a malleable but shape-retaining core.
All of the above references teach devices which cannot be used with minimally invasive surgical procedures (e.g., laparoscopy, retroperitoneoscopy, thoroscopy) and are limited in their ability to be molded into a specific shape.